In accordance with improvement of specifications of a set and use of a high bandwidth memory (HBM), an interposer market has grown. Currently, silicon has been mainly used as a material of the interposer, but development of a glass or organic interposers has been conducted in order to increase an area and reduce a cost. A connecting portion connecting the interposer to a mainboard, or the like, of the set, is called an underbump metallurgy (UBM) layer, and reliability of the connecting portion is significantly affected by a structure of the UBM layer, and the structure of the UBM layer thus needs to be optimized.
Particularly, various surface treatment processes have been performed on the UBM layer in order to improve bonding reliability. Electroplating is mainly used as the surface treatment as described above. In this case, processes of forming and removing plating lead lines are required, and a limitation in a design of a circuit pattern and a problem such as complexity of processes may thus occur.